“Is ten minutes enough?” Corstorphine directed this to the solicitor, who nodded sharply in his direction. He shut the door on them and walked back to stand in front of the crazy board with Frankie.

“What do you make of him, sir? Do you think he could have killed Oscar and the minister?”

“It’s possible. Sometimes it’s the most unlikely people who turn into killers. I guess we all have it in us if we’re pushed hard enough.” Corstorphine was puzzling over the board. “I don’t think Ackerman’s our man, though, Frankie. Being wrongly accused for poisoning raptors and losing your job, that’s bad enough, but is it sufficient motivation to risk a long spell in prison? I don’t think so. Then there’s the minister. There’s no obvious link between them. No, our murderer is someone who’s capable of cool planning and has an eye for making the punishment fit the crime. Whoever it is, they have planned this for a long time.”

“And they’re a dab hand with clockwork mechanisms,” Frankie added. “The clock repairer mentioned a French clockmaker based in Toulouse as the only person he knew who could make anything like this.” She pointed towards her desk where the boxed mechanism still lay.

“Our reporter’s French,” Corstorphine mused out loud.

“Why would there be any connection to France?” Frankie queried.

Reluctantly, Corstorphine added another name to the board – Josephine Sables. “I don’t know, Frankie.” He stroked an imaginary beard, deep in thought. “There’s something we’re missing, something we’ve not been told.”

Without warning, Corstorphine started pulling at the crazy board, lifting photographs and coloured string off in handfuls. “We’re looking at this all wrong. The orphanage is the common factor. The orphanage and the children who were abused and killed there.” He drew a rough circle in the middle of the board and labelled it ‘Orphanage’.

“These are the children we know about. Oscar, Simon Battle in Barlinnie and our butcher, William Booth.” Their names and photographs radiated out from the bottom of the central circle. “And these are the people who were either in charge, involved or accused of being abusers.” The minister, the laird, Lord Lagan and the old DI were placed at the top of the board. “The minister has been killed.” He drew a red line obliquely across the minister’s name, then did the same with Oscar. “If it’s someone looking for retribution then we should be concentrating on the orphans who are still alive.”

“Wasn’t Oscar one of the victims, though, sir?”

Corstorphine nodded. “Yes. Victim and also muscle for one of the alleged abusers.”

Frankie looked confused. “How does this relate to the death of June Stevens twenty years ago?”

“You say her notebook contained allegations of who was involved?”